Mogrify with Image Settings "-geometry 1000x1000" usually resize image of 1000 pixels wide or 1000 pixels high from 1.9MB to2.9MB to 190kb to 320kb. What makes it very useful is that you can resize a number of pictures all at the same time with just a single line command.

Now, I am ready to upload pictures to picasa album.

Apart from resizing, a useful trick is its ability to to reduce specific image to 50% from its original size, This is achieved by simply using its “-resize” option. See example below:

This command will give an output like the image below.

Now, we know that with mogrify, we can resize and reduce images, even multiple images at the same time.

What about file/ image format conversion?

For example, if you want to convert your .JPG file to .png file, use the “-format” option as this will do the trick.

Likewise, use the wildcard to do multiple files conversion

$mogrify -format png *.JPG

With this command, you are able to convert all our JPG images to the png format:

If this guide aint basic enough, don't forget to check the mogrify manual for more information on its usage.